1. Field of Invention
The present invention relates to a motor controller, in particular a motor controller having a multi-functional pin so that the number of pins is effectively reduced.
2. Description of Related Art
Typical communication interfaces for motor controller include I2C, SPI, SMBUS, etc., which need at least two communication lines: one for data transmission, and another for clock signal. FIG. 1 shows a prior art motor controller 10, and the motor controller 10 includes a control unit 11, a motor driving unit 12, and a speed transformation unit 13. The motor controller 10 further includes plural pins, wherein the control unit 11 is coupled to the pins H+, H−, and FG. The pins H+ and H− are coupled to a Hall sensor for receiving motor speed sensing signals, and the pin FG is for outputting motor speed information to an external device such as a CPU for judging the motor operation status. The motor driving unit 12 is coupled to pins VM, OUT1, OUT2, and GND, etc. for driving a motor, wherein the pin VM is for connecting to a motor voltage supply, the pin GND is a grounding pin, and the pins OUT1, OUT2 are motor driving pins for outputting motor driving signals; the number of pins may be different if the driving phase number of the motor is different, which can be modified according to practical need. The speed transformation unit 13 includes a memory 131 and is coupled to plural pins SDA, SCK, PWMIN. The pin SDA is for receiving data, the pin SCK is for receiving a clock signal, and the pin PWMIN is for receiving a pulse width modulation signal for speed control. The speed transformation unit 13 generates an output signal according to these signals, and sends the output signal to the control unit 11 for motor operation control.
When the aforementioned prior art motor controller is integrated in a single IC, the pin number directly affects the package cost and it is highly desired to reduce the pin number. In view of this requirement, the present invention provides a motor controller having a multi-functional pin to effectively reduce the pin number.
Taiwan patents No. 498163 (WO 2000/054282A1), No. 490670 (WO 1999/022289A1), No. 490670(WO 2000/054282A1), and No. I305647 (US 2006/0022707A1) disclose motor controllers but none of them provide the benefits of the present invention.